Cooling machine for oleaginous substances



y 11, 1954 w. SCHOTT ETAL 2,677,942

COOLING MACHINE FOR OLEAGINOUS SUBSTANCES Filed March 30, 1951 2Sheets-Sheet l W is I H TZRS:

5 hof a ee 2 He r -mgn Gab/magi M/he/rn Hoer y 11, 1954 w. SCHOTT m-AL2,677,942

COOLING MACHINE FOR OLEAGINOUS SUBSTANCES Filed March 30, 1951 2Sheets-Sheet 2 IN VENTORS Wa/fer Schofl Hugo Me/cherf Hermann GebhardfWilhelm Hom- Patented May 11, 1954 COOLING MACHINE FOR SUBSTANCES rearOFFICE OLEAGINOUS WalterSchott and Hugo 'Melchert, Hamburg- Bergeclorf,and Hermann Gebhardt and Wilhelm Hoer, Hamburg-Lohbrugge, Germany,

assignors to Aktiebolaget Separator, Stockholm, Sweden, a. corporationof Sweden Application March 30, 1951, Serial No; 218,326 6 Claims. (0].62-114) This invention has to in a rotary cooler for substances such asbutter, grease, margarine and the like, in which the substance to becooled is caused to flow in a rc1atively thin stream between closelyspaced cooling surfaces with a rotary means acting in the space betweencooling surfaces. Such coolers are known, employing conical chambers andr0- tating conical discs. The improvements relate in particular tocoolers for plastic substances, where the cooling produces a less fluentcondition and there is a tendency toward clogging of the flow passages.

The object of this invention is to provide a cooler that is simpler tomanufacture and that is efficient both from the standpoint of performingthe cooling and from the standpoint of avoiding clogging.

A preferred example of an embodiment of the invention is shown in theannexed drawings and is described below with reference thereto. In thedrawings:

Figure 1 is a View in vertical section of the pertinent parts of acooler embodying the invention, showing the driving mechanism andseveral cooling units acting in series; the top cover, inlet supplymeans and outer housings being omitted because not a part of the novelconstruction or necessary to an understanding of the improvement;

Figure 2 is a plan view of one of the novel rotating discs;

Figure 3 is a sectional view of the same disc, on the line 3-3 of Figure2, but also showing the scraper elements in place in the slots in thedisc;

Figure l is a view in elevation of a scraper element, looking at theside which is forward in the direction of rotation of the disc;

Figure 5 is an end view of the same; and

Figure 6 is a plan View of the same.

According to the invention, the cooling units of which there may be butone but usually there are several working in series, are of annularshape and planar; and aiiord closely spaced parallel planar walls whichare suitably cooled. A plane disc is mounted to rotate in the coolingchamber thus formed between these cooling surfaces. There is an inletand outlet for each coolins chamber, to permit continuous movement of dowith improvements the substance through'each chamber, and preferably theinlet and outlet are centrally located around the driving spindle of thedisc. The disc separates the inlet from the outlet and has an overflowclearance from the end wall of the annular cooling chamber at its outerrim so that the substance may flow to the underside of the disc afterpassing over its upper surface.

Preferably, the rotary disc is provided with scrapers to engage thecooling surfaces, and one improvement feature. has to do, with a formand arrangement of' scrapers. The scrapers are located in radial slotsin the disc and project on both sides'of the disc toward the coolingsurfaces. The arrangement is such as to cause certain scrapers to engageone of the parallel planar cooling surfaces while the others,alternately located, engage the other like cooling surface, theengagement being a forcible one which promotes effective clearing of thesurfaces. This action is created by an inclined forward face on thescraperwhich is presentedat one side of the disc sothat a wedge actionis induced by the resistance of the plasticsubstance to motion of thescraper through it.

1 Provision is made for use of identical scrapers, and for determining aunique fitting relation between such a scraper and each slot, thisrelation being reversed at alternate slots so that there is assurance ofhavingthe scrapers arranged to develop this forcible engagement withboth cooling surfaces, some of the scrapers acting on one sur-v face andthe alternate ones acting on the other surface. I

Improved means are clogging at the outlet from a comprising'both a screwpropulsion means at the final outlet and a means for interiorly heatingthe spindle of the machine in the region of the central outlets from theseveral cooling chambers, whereby to soften the outflowing material. Inone form the spindle has interior passages for circulating a heatingfluid to heat the spindle in the outlet region, and these passages aresurrounded by thermal insulation in the region of the driving gear ofthe spindle to prevent the gear from being overheated.

vThe preferred form of machine used as an illustration has a verticalspindle it on the upper part of which are mounted a suitable number ofprovided also to preventcooling chamber,

planar discs H (a, b, c, etc.) one above the other and separated fromone another by sleeves. These discs turn respectively in a like seriesof cooling chambers 52 (a, b, 0, etc.) formed by the fixed part of thestructure. Speaking generally, this fixed structure comprises a seriesof suitably shaped annuli E3 to which are secured thinwalledhorizontally disposed containers [4 for a cooling medium. The outerwalls of these containers present parallel planar cooling surfaces whichwith the outer end-wall provided by the annulus i3 define the coolingchambers I2, in which the discs ll turn. The discs carry scrapers I5 inradial slots, as described more fully below. At the lower part of thespindle I0 is a conventional worm-and-gear driving means It within ahousing having upper and lower parts l1, is which include bearings 19,for the spindle.

The substance to be cooled is fed in at the top and passes through theseveral cooling chambers in series. At each cooling chamber there is acentral inlet and outlet separated by the rotary disc. The substancebeing cooled moves horizontally outward over the top of the disc whereit is subject to the cooling action of the planar wall of the coolantcontainer above, thence over the outer rim of the disc which is spacedfrom the end-wall of the chamber; and finally back to the central outletthrough the space between the lower side of the disc and the planar wallof the coolant container beneath, which forms the lower wall of thecooling chamber. Final discharge is at the bottom of the series ofunits.

No novelty is presently asserted as to the details of construction ofthe fixed parts of the cooling units, and any suitable construction maybe employed, including appropriate passages to introduce and to withdrawthe cooling medium, continuously if desired, and to permit a fiow of thecooling medium from one container to the next in series and through theindividual containers. For the purpose of the present novelty, it issufficient that the fixed parts of the structure provide one or moreshallow annular cooling chambers defined by parallel plane surfaceswhich are cooled by a cooling medium flowing over or in any event incontact with their obverse surfaces, so that a transfer of heat mayoccur from the substance being cooled to the cooling medium throughthese planar bounding walls. Each cooling chamber must moreover be ofsuch radial extent relative to the rotary discs that there is aclearance between the end wall of the chamber and the outer edge of thedisc, to permit flow of the plastic substance over the rim of the discto the space beneath the disc. Finally, there must be an inlet andoutlet for each cooling chamber, preferably in the form of centralopenings around the spindle, one above and one below each disc. Theplastic substance then flows down onto the disc at the center, movesradially outward on the upper side of the disc and over its rim, andfinally radially inward on the lower side to the outlet. It is subjectedto a cooling action in its passage in both directions.

For purposes of illustration, a particular preferred form of fixedstructure is described. The lowermost annulus ita has a web 2| extendingto a circle close to the spindle Hi, leaving a central outlet opening 22in alignment with a like opening 23 in the upper wall 24 of a box 25which forms an annular collecting chamber 26 with a side outlet 21 forcontinuous discharge of the cooled substance.

This lowermost annulus [3a has an annular step 28 at its inner side, andan upstanding annular rib 29 at a mid-point on the web 2 I, and anannular rib 35 at its inner rim. These ribs upport thin-walled member 3|which with the spaced web 2! forms the final container Ma for thecooling medium and also constitutes the lower planar cooling surface ofthe final cooling chamber iZa. This thin-walled member 3i overlies theside face of the inner rib 30, the step 28 and the top surface 32 of theannulus l3a, being secured in a way to prevent leakage at the joints.

The upper planar cooling surface of the lowermost cooling chamber l2a isformed by the lower wall of a further section Mb of the container forthe cooling medium. This section Mb is made of thin-walled metalextending inwardly from the joint between annuli [3a and 13b to a circlenear to but spaced from the spindle iii, then upwardly and back to thestep 281) on annulus Rb and the joint between annuli I31) and I30. Theupper wall of this container section Mb forms the lower planar coolingsurface of the next higher cooling chamber liib. Being spaced from thespindle at its inner end, this section Mb defines the central inlet tothe cooling chamber [2a and the central outlet from the next highercooling cham ber lZb. A ring 31 supports and spaces the planar walls ofthis container section Mb. Other cooling chambers are similarly providedby additional units similarly constructed. The uppermost unit (notshown) may be made the same as the lowermost unit Isa, but inverted.

Each horizontal planar disc II has a series of radially extending slots40, here shown as four in number, which receive scrapers l5 as shown inFigures 3-6. Each scraper i5 is so shaped to have a free fit in the slotbut is thicker vertically so as to extend above and below the disc. Itsvertical dimension is slightly less than the spacing between the upperand lower horizontal cooling urfaces. At the forward face of eachscraper, in the direction of rotation of the disc, is a camber 4|forming an inclined plane. When this camber is at the lower part of theforward face of the scraper, so as to present itself below the discwhich carries it, the resistance of the plastic substance to motion ofthe scrapers creates a wedge action because of this inclined surface andforces the scraper upwardly into contact with the upper horizontalcooling wall. Conversely, when the camber is at the upper part of theforward face of the scraper, so as to present itself above the disc, thesame action forces the scraper against the lower horizontal coolingwall. This forcible engagement assures a more effective scraping actionon the wall toward which the scraper is forced, and thereby maintains ahigh rate of heat transfer.

The several scrapers 15 are so placed in their respective slots 40 thatone presents its inclined face at the upper side above the disc and thenext scraper presents it at the lower side, below the disc; and so onalternately in the series around the disc. Thus, half of the scrapersare forced against the upper cooling wall and half against the lowercooling wall of each cooling chamber.

To permit the use of identical scrapers in all of the slots, and at thesame time to assure preservation of this alternate wedge action of thecambers or inclined forward surfaces, we provide an arrangement ofinterfitting or keying parts on one wall of the scraper and one wall ofeach slot. This may take various forms, but a convenient one employs apin 42 inserted into a bore 43 in the disc, the circle of which boreextends into the slot. There is a complementary cut 34 in the side ofthe scraper, so that when the scraper is placed in the slot with itsside out 24 adjacent the bore 23 in the disc the pin 2 can be insertedto key the two together, without interfering with the freedom of thescraper to move up or down in the slot. The important thing is therelative location of this interfitting means in the different slots.This will be understood upon consideration of the two adjoining slots inFigure 2 which are marked A and B. Viewing each from its outer end,looking toward the center, it will be seen that the interfit at slot Ais at the left and nearer the center, while at B it is at the left butnearer the outer end, and that in both it is spaced the same distancefrom the adjacent end of the slot. A scraper can be keyed in each slotin but one position, and in order to be keyed in slot B it must beturned upside down relative to its position in slot A, therebypresenting its wedge face at the opposite side of the disc.

To prevent clogging at the bottom outlet opening 22, we employ a worm 45mounted to turn with the spindle it and so threaded as to force theplastic substance downwardly into the outlet box 25.

To lessen any tendency toward outer rims of the discs, where stanceoverflows, we

clogging at the the plastic subprovide a series of holes it around thedisc near its outer edge. To prevent clogging at the inner passagesconnecting each cooling chamber with the one beneath, where the cooledsubstance is less affected by the motion of the discs and scrapers andis in contact with the spacers ll which separate the discs and surroundthe spindle it, we make the spindle hollow, with a closed top, and weprovide an open-ended pipe 48 extending up within the hollow part of thecolumn to near its top. A bottom casting ie has an inlet connection 59for a heating fluid delivering to the central pipe 48 and a separateoutlet connection 5 i, which communicates with the annular space 52within the spindle and around the central pipe 48. This permits acontinuous flow of a heating fluid, liquid or vapor, to heat the spindleand its surrounding sleeves; also to heat the worm =35 at the finaloutlet 23, 24.

A further provision, to protect the driving gear l6 from beingoverheated by this fluid, is an insulator consisting of a body of aircontained between the inner wall of an enlarged part 54 of the hollowspindle and a cylindrical partition 55 sealed at both ends to thespindle as shown.

Other heating means, such as an electrical resistance element, may beused to apply heat to the splindie in the region where it adjoins theinner flow passages forming the cooling chamber units, or at the finaloutlet of the lowermost chamber. Where a fluid heating medium isintroduced at the bottom of the spindle, so as possibly to affect thepart of the spindle near the driving gear, other forms of thermalinsulation may be used to protect the driving gear from overheating.

In the foregoing, the improvements have been described in terms of apreferred machine having a vertical spindle, wherein the coolingsurfaces and co-acting discs are horizontal. The improvements are notlimited to that use but may be employed where the cooling surfaces anddiscs are vertical, but nevertheless are planar.

We claim:

1. In a cooling machine, means forming an annular cooling chamber havingparallel closely planar cooling surfaces, chamber, and a plane discmounted to rotate between said cooling surfaces, said disc having atleast two radial slots, scrapers projecting beyond the surfaces of thedisc and movable freely in the slots in a direction normal to the disc,one scraper having an inclined forward face presented at one side of thedisc and the other scraper having an inclined forward face presented atthe other side of the disc, each inclined forward face being partlyopposed to the adjacent planar cooling surface, whereby said scrapersare forced into engagement respectively with opposite cooling surfacesby a wedge action induced by passage of the scrapers through thesubstance being cooled.

2. In a cooling machine embodying the subject of claim 1, interfittingmeans in each scraper and slot determining a fitting relation in whichthe scraper may be placed in the slot, the interfitting means beingreversely located in the two slots so that an identical scraper fittingin one presents its inclined face at one side of the disc and placed inthe other presents said face at the other side of the disc.

3. In a cooling machine, means forming a cooling chamber having parallelspaced walls affording planar cooling surfaces, an inlet and an outletfor delivery of a substance to be cooled through said chamber, a planedisc parallel to but spaced from said cooling surfaces and spaced wallsaffording an inlet and outlet for the disc, the disc having recesses,and scrapers disposed in said recesses and freely movable therein in adirection perpendicular to said planar cooling surfaces.

i. In a cooling machine, means forming an annular cooling chamber havingparallel closely spaced walls affording planar cooling surfaces, acentral inlet at one side of said chamber and cular disc mounted toseparate said inlet and outlet and to rotate between said planar coolingsurfaces in spaced relation thereto, said disc having at its outer riman overflow clearance from of said chamber, whereby the disc divides thematerial flowing through said chamber into two layers contacting,respectively, the planar cooling surfaces and joined at said outer rimof the disc, said disc having at least two angularly spaced radialslots, and scrapers proin a direction toward the planar coolingsurfaces, one scraper having an inclined forward face presented at oneside of the disc and the other having an inclined forward face presentedat the other side of the disc, each inclined forward face being partlyopposed to the adjacent planar cooling surface, whereby said scrapersare forced into engagement respectively with opposite cooling surfacesby a wedge action induced by passage of the scrapers through thesubstance being cooled.

5. In a cooling machine, means forming an annular cooling chamber havingparallel closely spaced walls affording planar cooling surfaces, acentral inlet at one side of said chamber and a central outlet at theopposite side, a plane circular disc mounted to separate said inlet andoutlet and to rotate between said planar cooling surfaces in spacedrelation thereto, said disc having at its outer rim an overflowclearance from the outer wall of said chamber, whereby the disc dividesthe said chamber into two layers contacting, respectively, the planarcooling surfaces and joined at said outer rim of the disc, and a screwpropulsion element mounted in the outlet from the cooling chamber torotate with said disc, and arranged as to direction of action to assistoutflow of the substance being cooled.

6. In a cooling machine as defined in claim 5, a rotary spindle on whichsaid disc is mounted, and means for heating the spindle interiorly inthe region of said outlet and screw propulsion means.

References Number Number 8 Cited in the file of this patent UNITEDSTATES PATENTS Name Date Recht July 8, 1919 Hall Nov. 8, 1932 StoneSept. 24, 1940 Koropchak Jan. I, 1941 Birdseye Jan. 14, 1941 FOREIGNPATENTS Country Date Italy Nov. 16, 1937

